A 2023 guideline development effort by the Society of Critical Care Medicine (SCCM) focused on creating evidence-based recommendations for rapid sequence intubation (RSI) in critically ill adult patients. The 2023 SCCM guidelines on RSI identified gaps in the current literature, which often result in practice variations and controversies relating to airway management. The results underscored the recommendation to use neuromuscular-blocking agents (NMBAs) when a sedative-hypnotic agent is administered for intubation, due to improvements in first-pass success rates and reductions in complications such as aspiration. The guidelines also suggested head and torso inclined positioning during RSI, preoxygenation methods using high-flow nasal oxygen or noninvasive positive pressure ventilation for patients with severe hypoxemia, and the administration of a sedative-hypnotic agent even in cases of hemodynamic instability. Notably, the expert panel did not discuss the use of lidocaine, nor did they provide any recommendations for the use of any medications for pretreatment. [1]
A 2023 review provides an extensive examination of pharmacotherapies used during the RSI process in the emergency department (ED) setting. The paper emphasizes the critical selection and dosing of pretreatment, induction, and neuromuscular blocking agents to facilitate successful intubation, while minimizing adverse effects and optimizing the intubation conditions. The authors discuss the utility of pretreatment agents such as atropine, lidocaine, and fentanyl, noting their limited role outside of select clinical scenarios due to insufficient evidence for improved outcomes. Lidocaine, a voltage-gated sodium channel blocker, is an antiarrhythmic and local anesthetic with a theoretical benefit in RSI for conditions like traumatic brain injury (TBI). It’s thought to blunt the catecholamine surge, thereby reducing increases in intracranial pressure (ICP), intraocular pressure, and mean arterial pressure (MAP). However, robust data supporting its use as a pretreatment agent are lacking. Studies have shown lidocaine can reduce ICP and MAP, but not specifically in the context of RSI in the ED, where measuring ICP is difficult. A retrospective ED study on TBI patients found no significant benefit, and a small prospective trial showed it blunted changes in MAP and heart rate, but didn't assess ICP outcomes. While lidocaine is believed to suppress cough and prevent bronchoconstriction, studies demonstrating these effects were conducted without NMBAs, which are standard in RSI. Given the conflicting and low-quality data, the use of lidocaine for pretreatment in RSI is not recommended. [2]
A 2001 review article explores whether pretreatment with intravenous lignocaine/lidocaine in patients with head injury undergoing RSI leads to improved neurological outcomes. The review highlights that laryngeal instrumentation and endotracheal intubation are associated with transient increases in ICP, which are particularly risky for head injury patients due to potential reductions in cerebral perfusion and increased secondary brain injury. Despite the routine use of intravenous lidocaine in the United States to attenuate this ICP rise, the review's literature search reveals a lack of evidence directly linking lidocaine pretreatment with improved neurological outcomes post-RSI in major head injuries. The review identifies six papers that individually address parts of the question, yet none directly answer it. These studies primarily involve patients undergoing elective neurosurgery rather than those with acute traumatic brain injuries. The findings suggest that while lidocaine may attenuate the rise in ICP associated with laryngoscopy and intubation in elective procedures, there is no substantial evidence supporting its use in RSI for head injury patients. [3]
Pediatrics:
According to a 2018 review, the use of lidocaine as a neuroprotective agent for elevated ICP is still considered to be controversial in pediatric trauma patients. No studies are available to assess lidocaine’s efficacy for reduction of ICP due to the inability to obtain real-time measurements of ICP in the emergency department. Data from other settings has thus been extrapolated, with studies showing intravenous lidocaine at 1.5 to 2 mg/kg results in a decrease in ICP by 12 mmHg, more than 30% from baseline before endotracheal suctioning in closed head injury patients in the intensive care unit. The optimal dose is reported to be 1.5 mg/kg administered 2 minutes before induction to avoid hypotensive adverse events. Notably, the evidence presented in this review was from studies in adults, even though the review itself focused on pediatric patients. [4]
An older 2005 review also reported a lack of adequate data for determining the appropriate use of lidocaine in this setting. At the time this review article was published, the recommended pediatric dose of lidocaine was 1 to 2 mg/kg given intravenously 2 to 5 minutes prior to intubation. Although lidocaine was reported to be widely used, no studies were available to assess its efficacy for improvement of neurological outcomes for patients undergoing RSI after acute traumatic brain injury. Efficacy data from adult patients was stated to be conflicting. Potential benefits of lidocaine use must be reconciled with risks, including cardiovascular side effects as well as the addition of yet another complication in the RSI process. [5]
More dated literature mentions the use of lidocaine as pretreatment in children and infants due to their more prominent vagal response to endotracheal intubation. Based on data available at the time, mixed results were reported for inhibition of hypertension and tachycardia with intravenous lidocaine. For laryngoscopy, the recommended dose of lidocaine was 1.5 to 3 mg/kg intravenously 2 to 5 minutes prior to procedure. Maximum efficacy is reached in 3-5 minutes after administration. Topical lidocaine was suggested to be effective in blunting reactions to placement of the endotracheal tube, as lidocaine directly to the trachea may be a challenge. Some authors consider lidocaine to be the safest premedication agent regarding risk of respiratory depression, however, the potential benefit is still considered controversial for pediatric patients. Nebulized lidocaine solution at doses of up to 5 mg/kg or direct topical lidocaine at 3 mg/kg may be considered to decrease risk of systemic toxicity. [6], [7]
A retrospective, single-center, chart review evaluated an RSI protocol for pediatric patients from 1996 to 2000. The RSI sequence for children involved pre-oxygenating and preparing drugs for the first 5 minutes; pre-treating with atropine 0.02 mg/kg and lidocaine 1 mg/kg via intravenous push (IVP); administering sedation with etomidate (preferred) or thiopental; administering a paralytic of succinylcholine or rocuronium; and intubation. No specific formulation or dose of lidocaine solution was specified. Of the 83 pediatric patients (mean age, 8.6 years; range, 18 months to 17 years), only two (2.2%) patients did not receive lidocaine. Twenty-five of 71 (35.2%) trauma-related intubations were due to assaults, falls, or closed head injuries. Overall, this protocol was found to work well in an urban Level 1 trauma center. [8]
In a 2025 open-label pharmacokinetic and safety evaluation, researchers investigated serum lidocaine concentrations and safety outcomes following endotracheal administration in a cohort of critically ill pediatric patients. Conducted at Norton Children’s Hospital, this phase I study targeted a population of 21 endotracheally intubated infants and children who required suctioning, assessing for potential cardiovascular instability or increased intracranial pressure. The methodology encompassed administering weight-based lidocaine dosing according to age brackets, where participants aged over 38 weeks of estimated gestational age and under 3 years received 0.5 mg/kg/dose, and subjects aged 3–18 years received 1 mg/kg/dose. Blood concentrations were monitored at designated intervals up to 120 minutes post-administration. The study confirmed the absence of toxic serum lidocaine concentrations, with detectable levels in only 4 subjects aged over 3 years at early sampling points, thereby demonstrating a favorable safety profile. The study further evaluated secondary outcomes concerning adverse effects, such as cough, bronchospasm, or significant changes in cardiac or respiratory function. Remarkably, no adverse clinical events or toxicological manifestations were observed across the participant pool. While mild fluctuations in vital signs were recorded, these self-resolved without medical intervention. This suggests the administered doses of lidocaine are safe within this pediatric patient setting. The research not only underscores the potential utility of lidocaine in mitigating adverse responses associated with endotracheal suctioning but also posits foundational pharmacokinetic data that could guide subsequent dose-escalation and efficacy studies aimed at optimizing endotracheal intubation management in critically ill pediatric populations. [9]